Shakespeare’s society relied on wood as fuel but as our society becomes increasingly urbanised, energy demand continues to increase; it is expected that in 2035, demand will have risen by a staggering 37%((BP. “BP Energy Outlook.” Accessed January 19, 2017. http://www.bp.com/en/global/corporate/energy-economics/energy-outlook.html.)). Currently, 84% of global energy needs are supplied by energy from hydrocarbons, with oil accountable for 35%. Though crude oil has proven to be a valuable energy resource (infrastructure in place, energy efficiency), the depletion of conventional reservoirs mean we must look for a new source. Nuclear energy offers an energy per unit mass that is ten times greater than that for oil, whilst alternate energies offer an exponentially lower carbon output. Unfortunately, each of these comes with its own complications too, highly radioactive waste and inefficient energy supply respectively.
A popular solution to the energy crisis is to turn to natural gas as our primary source of energy. Natural gas is compatible with existing infrastructure and has a carbon output which is three times smaller than that for crude oil. Crucially, the recent discoveries of large volumes of Shale Gas reserves across the globe offer an available source. The Mainstream media has divided public opinion on Shale Gas; whilst many know it as the golden goose by which the US will reach a sustainable energy future, it is also associated with “environmentally hazardous” fracking techniques((Drill or Drop? “Shale gas: golden goose or expensive short-term hit?.” Accessed January 19, 2017. https://drillordrop.com/2015/02/10/shale-gas-golden-goose-or-expensive-short-term-hit/)). Correcting this negative public opinion is one challenge an energy company would face. Furthermore, the dramatic drop in oil price has produced a tight financial climate where largely, funding for new projects has been withdrawn or suspended.
However, many would argue that the Shale Gas fracking will be the next big thing in the energy industry. According to BP’s 2035 Energy Outlook, demand for natural gas will rapidly increase as large parts of Asia industrialise. Projections show that more than half of this demand could be met by Shale Gas production, suggesting it will hold an important position in the future energy market. Natural gas is cleaner in terms of CO2 emissions than other fossil fuels, and also has a higher Energy Return on Energy Investment (EROEI) than renewable energy so there may also be strong political backing for development of such projects((Carbon Brief. “Energy return on investment – which fuels win?” Accessed January 19, 2017. https://www.carbonbrief.org/energy-return-on-investment-which-fuels-win )).
As we become more dependent on natural gas as a means of energy production super-majors like BP will be able to invest new Shale Gas production technologies that address the associated environmental, economic and social concerns. Today, tight gas is produced by fracking, a process where water mixed with sand and chemicals is pumped underground at a high pressure to “fracture” the rock, allowing the release of trapped natural gas.
An obvious challenge an energy company will face with fracking, is regarding the large volume of expensive potable water (2-8 million gallons per frack) used in the process; in many agricultural settings operating companies will outbid farmers for water, creating public aversion to the development of Shale Gas projects((National Geographic Creative. “Water Use For Fracking Has Skyrocketed, USGS Data Show”. Accessed January 19, 2017. http://news.nationalgeographic.com/energy/2015/03/150325-water-use-for-fracking-over-time/)). A recent BP project in Pennsylvania has, however, pioneered the use of foam fracking technologies, presenting a solution; nitrogen and water are integrated in the fracking mix (N2 content varies between 53-90% depending on well depth), resulting in a significant decrease in the volume of water required((Shale Gas International. “Is Using Nitrogen For Water-Free Fracking The Way Forward?”. Accessed January 19, 2017. http://www.shalegas.international/2014/09/02/is-using-nitrogen-for-water-free-fracking-the-way-forward/)).
The contamination of water supplies is also a serious concern. Fracking fluids containing carcinogenic benzene and acrylamide are released into drinking water which can cause serious health issues, including cancer, infertility and birth defects. Fracking has also been linked to an increased level of radium reaching the surface; the 10-40% of recoverable water shows a three-hundred-fold increase in radiation levels((Frack Off. “Fracking Impacts – Radioactive Contamination”. Accessed January 19, 2017. http://frack-off.org.uk/fracking-impacts/radioactive-contamination/)). The disposal of this water must be regulated in a safe, environmentally friendly manner. One solution, which has gained approval in the US, is using the water to make the cement which will be put back into the ground during the well-drilling process.
The abundance of methane escaping from underground traps is another issue, contaminating tap water and making a significant contribution to the greenhouse effect, to a much greater extent than the reduced CO2 emissions from natural gas combustion do. However, investment from major oil and gas companies like BP has led to the development of new cements for well casing, and this has been extremely effective in managing this problem. These cements use organic resin technology, which increases the adhesive properties of cement and also contain compounds known as retarders which slow down the hardening process. For wells exceeding depths of 1500m, this is extremely advantageous as it allows sufficient time for the cement to fill up gaps before it solidifies, blocking off escape pathways for the trapped methane((Applied Mechanics And Materials.Fu, Jun Hui, Guang Cai Wen, Fu Jin Lin, Hai Tao Sun, Ri Fu Li, and Wen Bin Wu. “Hydraulic Fracturing Experiments at 1500 m Depth in a Deep Mine: Highlights from the kISMET Project”. Accessed January 19, 2017. https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2017/Oldenburg.pdf)).
In some areas, major oil and gas producers have taken an alternative approach to dealing with these challenges: to remove fracking from the equation altogether. A combination of directional drilling and acidizing, which involves dissolving the carbonate cement in reservoir rock to re-establish natural fissures, has yielded excellent results for tight gas production in the US. The de-liquefaction of tight gas reservoirs (removal of water) as also proven to be successful, though at present this solution is not one that is economically viable.
So, are we to frack or not to frack? History has shown that fossil fuels have earned their place as kingpins in the energy market, because of the universal agreement that the energy generated comes at the lowest opportunity cost. New innovations like water-free fracking, which utilises a propane based gelled fluid instead, or infra-red technology, which enables methane gas leaks to be detected and plugged up, offer us the means to enhance this process further still. Shale Gas fracking is the next step in ensuring that there is an efficient and secure future for global energy.
Figure 1: An oil derrick at a fracking site for extracting oil outside of Williston, North Dakota.
Figure 2: High pressure water is used to release trapped gas from tight reservoir formations.
Figure 3: Shale gas protestors make their feelings clear.
Figure 4: Methane contamination observed in the local water supply.